Error Pandas read csv low memory and dtype options

Question

When calling

df = pd.read_csv('somefile.csv')

I get:

/Users/Niraj/anaconda/envs/py27/lib/python2.7/site-packages/pandas/io/parsers.py:1130: DtypeWarning: Columns (4,5,7,16) have mixed types. Specify dtype option on import or set low_memory=False.

Why is the dtype option related to low_memory, and why would making it False help with this problem?

Answer 1

Hello @kartik,

Try this:

dashboard_df = pd.read_csv(p_file, sep=',', error_bad_lines=False, index_col=False, dtype='unicode')

According to the pandas documentation:

dtype : Type name or dict of column -> type

As for low_memory, it's True by default and isn't yet documented. I don't think its relevant though. The error message is generic, so you shouldn't need to mess with low_memory anyway.

Hope this is helpful!

Thank You!!